Are you saying that a tiny waterfall aquarium type pump will give you more DO than airstones?
I am saying that the aquarium guys don't add warmed air to their carefully prepared environments. These are much less stable, being un-insulated glass. But, consider the volume. A 10 gal fish tank is small. But, a 10 gal res, is all I need. (well, I use 3 reservoirs with different nute strength)
So, the question however, shows, perhaps a hole in the understanding of what we are doing.
What gives more DO, is not the question. DO is saturated at a certain temp and atmospheric pressure, and SALINITY. We don't want super-saturated, that can be root poison. And it is very difficult to achieve over saturation at normal atmosphere with any technique., lucky for us, huh?
Well, we are not working with Sea water where most all saturation occurs in this world. But, the nutes are a saline solution, just no sodium salt.
Also, Zero DO water, is not impossible and has to be produced for live steam. But, to get water with no gas saturation is a special process, again.
WATER is ALREADY SATURATED. Yeah. I found with my DO kit, there is so much DO in water already because of affinity, It is the most natural thing that just happens by itself.
When we get involved, we let the water go still. Back before we knew, I can imaging this.
The fish for supper, die. WTF!!!!???? Damn cave life. No one knows shit about anything, yet. Stir the water, Grog... Oh, who said that? Good idea. Keep the water moving and the fish don't die. Why??? Who cares, lets eat.
Since it has to do with salt and surface and temp, my RO water comes out of the barrel saturated. I can measure the DO at 9% and that is all you get in our working range of temp and salt.
So we just have to keep that DO by turning up the water from the bottom and exposing it to the atmosphere's pressure.